init_normal_area was mapping identity lookups (phys = virt) from 0,
leading to many undetected null pointer dereferences in init_pt (but
not in new process page tables leading to odd behaviour)
This also makes the code use the set_pt_large_page() function, cleaning
it up a bit
Change-Id: I22889031de26a7e48501b0eb4d453ca62e671835